Device for testing static accumulating properties of textile fibers



R. v. OTT 2,421,430

DEVICE FOR TESTING STATIC ACCUMULATING PROPERTIES OF TEXTILE FIBERS June 3, 1947.

Filed June 17, 1943 INVENTOR.

RALPH V. OTT.

I ATTORNEYS Patented June 3, 1947 DEVICE FOR TESTING STATIC ACCUMULAT- ING PROPERTIES OF TEXTILE FIBERS Ralph V. Ott, Narrows, Va., assignor to Celanese Corporation of America, a corporation of Delaware Application June 17, 1943, Serial No. 491,145

4 Claims.

This invention relates to a testing device, and relates more particularly to a device for measuring the amount of static electricity present on textile materials.

' An object of the invention is the provision of a device for measuring the static electricity produced on fibers by frictional contact with metals, glass, porcelain, pressed fiber and other substances with which the fiber might contact in being processed to a yarn or fabric.

Another object of the invention is the provision of a device for measuring the effectiveness of various dressings and finishes applied to the fiber in reducing the static charge induced on the fiber and in conducting from the fibers any static produced thereon.

Other objects of the invention will appear from the following detailed description.

In the drawing:

Figure 1 is a side elevational view of the device of my invention, and

Figure 2 is a detailed view showing the means for supporting the balance lever.

Like reference numerals indicate like parts throughout both views of the drawing.

During the processing of fibers, and especially artificial or synthetic fibers, to yarns there is sometimes built upon the fiber a static charge which makes the processing difficult. Heavily charged fibers tend to adhere to certain parts of the machines, to fly away from other machine parts, and to repel each other, thus causing processing difiiculties. Dressings and finishes have been developed to overcome these difiiculties and have met with considerable success. To ascertain the value of the dressings, however, it was necessary to run a full batch of the fibers through standard equipment and note the effect. As the dressings change in properties with changes in humidity and temperature, the evaluation of a particular dressing was both costly and time consuming. Often many days were required to change the humidity and temperature surrounding the large standard equipment. The present invention overcomes this costly and time consuming method of testing the eifectiveness of'the dressings by measuring the amount of static that can be imposed upon small samples of fibers by a device which is relatively small and compact so that it can be enclosed in a suitable casing where temperature and humidity can be very readily changed and accurately controlled. Also by exchange of readily removable friction discs of different substances, the efiect of said diiierent substances on the material being tested may be ascertained.

Referring now to the drawing for a detailed description of my invention, the reference numeral I generally indicates a base or stand provided with a foot 2 of a weight suflicient to prevent undue vibration, and an upright or standard 3. A, motor 4 having a suitable power connection v5 is fixed to the upper portion of standard 3 so that the shaft 6 thereof is in a vertical position. On the lower end of the shaft 6 is suitably attached a nipple I, which may be formed integral with a disc 8. The disc 8 is provided with three or four holes through which studs 9 and their surrounding insulators ll pass, The insulators may be of sulphur in which case they may be cast in place, or they may be of porcelain, glass, plastic, etc. The insulators are held in place on the studs 9 by washers l2 and nuts I3. The lower end of the studs 9 are tapped into a collector plate It which may be of iron, copper, or other substance which it is desired to test frictionally with the fibers. Various plates l4 for testing with the fibers may be prepared and may be interchanged by the removal of the nipple 1 with its attached plate from the shaft 6 and substituting therefor another nipple carrying the type of plate desired.

Also mounted on the standard 3 is a bracket l5 having integral therewith two or more horizontally extending arms l6 provided at their.

outer ends with guide slots H. The bracket l5 may be attached to the standard 3 by bolts 18 as shown, or by welding or other suitable means. Slidably inserted in the slots 11 is a bar I9, with its top end 2| making a sliding fit into the nipple 34 and pivoted at its lower end to a link 22 by a pin 23.

rangement urges the bar 19 upward by a controlled force governed by the position of counter balance weight 33 along the balance lever 32.

A nipple 34 Welded or otherwise fastened to a plate 35 is provided for sliding-over the top end The upper arm 16 of the bracket I5 is 1 provided with a second slot 24 through which is of bar I9. The plate 35 has anti-rotation plugs 36 adapted to register with wells 31 in the bottom of a cup 38 that is supported thereby. The pin 25, referred to above, is threaded through the plate 35 so that one end projects above the'plate to form a plug similar to plugs 36. The other end, as indicated above, extends through the slot 24 in the arm l6, which construction prevents rotation of the cup 38 and strain on the bar IS. The bottom of the cup 38 is roughened or is lined with sand paper 39 or other such material adapted to prevent the sample of staple fiber 4| from being spun around by the action of the collector plate l4.

On a plate 42, electrically insulated from the standard 3 but supported thereby, is mounted a contact finger 43 provided with an insulated key 44 which when manually pressed efiects a contact between the collector plate I4 and the contact finger 43. The contact finger 43 is connected to a control panel 45 by a lead-in wire 46 while the stand and all related parts of the device are grounded by a wire 41 connected to the ground terminal 48 of the control panel 45. A grounding connection 41 is provided for grounding the device and its electrical circuits.

The control panel registers the static charge developed upon the sample 4! by the friction between said sample and the revolving plate 14. To this end, the lead-in wire .46 is connected to a terminal which is connected by lead 52 to one side of a variable condenser 53. From the lead 52 a lead 54 is run to a manually operated switch 55. The switch 55 is in turn connected by a lead 56 to the plate 51 of an amplifier tube generally indicated by reference numeral 58. The grid 59 of said tube is connected by a lead 6! to a microammeter 62 that is connected by lead 63 to a manually controlled variable resistor 64 and through a resistance coil 65 to a battery 66 or other suitable source of electric power. The battery 66 is connected to a lead 61 to the condenser 53 and to the filament 68 of the tube 58. The other end of the filament 68 is connected by a lead 69 to a reslstor H then by lead 72 to lead 63 to complete th filament circuit of the tube. In place of the control panel 45 there may be employed any other registering devices well known in the art, as well as attachments that show on a chart a voltagetime curve or the like.

The whole device may be enclosed in a carrying case (not shown), similar to those used to enclose laboratory balance scales, equipped with a connecting cord and plug for connecting the motor 4 with a source of current. Desiccator jars may be placed in such an enclosed case to reduce the humidity or moist humidor blocks may be employed to increase the humidity while the temperature may be controlled by any suitable means such as heating coils, ice cubes, etc. Naturally, for standardizing the conditions, the case may be equipped with humidity indicators and thermometer.

In operation, pressure downward on the cup 38 permits access to the interior of the cup so that a sample 4| may be placed therein or removed therefrom and permits replacement, if desired, of the plate 14. A sample of fibers or fibers coated with a dressing is spread in bottom of the cup 38 which when released is forced upward by the weight 33. The external conditions having been brought to the desired constant the motor 4 is caused to rotate. After the motor has been allowed to rotate for a definite number of revolutions, or for a definite period of time, the cup-38 is pressed downward so that the sample of fibers is no longer in contact with plate l4. The key 44 is then depressed and the relative static charge is registered on the microammeter 62.

Although the device is designed primarily for testing textile fibers and/or various dressings applied to textile fibers, it may be employed for testing other materials such as ground cork, insulating pellets, etc. Examples of textile fibers are fibers made of or containing organic derivative of cellulose such as cellulose acetate, cellulose formate, cellulose acetobutyrate, ethyl cellulose, methyl cellulose, benzyl cellulose, etc.; fibers of regenerated or reconstituted cellulose; natural fibers such as cotton, wool, flax, hemp, etc.; and fibers made of synthetic linear polyamide condensation products.

It is to be understoodthat the foregoing detailed description is merely given by way of illustration and that many variations may be made therein without departing from the spirit of my invention.

Having described my invention, what I desire to secure by Letters Patent is:

1. In a device for testing the electrical conductivity and static accumulating properties of textile fibers wherein there is employed a means for measuring an electric potential, a base for holding a sample of fibers to be tested, a rotatable plate normally out of contact with said base, means for causing said plate to come into contact with the sample of fibers disposed on said base, means for rotating said plate whereby a frictional contact with a sample of fibers is effected, supports on which said plate rotating means is mounted, means for insulating said plate from said means for rotating said plate and means, carried by said support and normally insulated from said base and said rotatable plate, movable into contact with said plate for carrying any charge developed thereon -to said measuring means.

,2. In a device for testing the electrical conductivity and static accumulating properties of textile fibers wherein there is employed a means for measuring an electric potential, a base for holding a sample of fibers to be tested, a rotatable plate normally out,of contact with said base, means for moving said base in the direction of said plate so as to cause said plate to come into contact with the sample of fibers disposed on said base, means for rotating said plate whereby a frictional contact with a sample of fibers is effected, supports on which said plate rotating means is mounted, means for insulating said plate from said means for rotating said plate and means, carried by said support and normally insulated from said base and said rotatable plate,

movable into contact with said plate for carrying any charge developed thereon to said measuring means.

3. In a device for testing the electrical conductivity and static accumulating properties of textile fibers wherein there is employed a means for measuring an electric potential, at base for holding a sample of fibers to be tested, a rotatable plate normally out of contact with said base, means for moving said base in the direction of said plate so as to cause said plate to come into contact with the sample of fibers disposed on said base, said means including a lever arm operatively connected to said base and a counter-balance weight carried by said lever arm, means for rotating said plate whereby a frictional contact with a sample of fibers is effected, supports on which said plate rotating means is mounted,

means for insulating said plate from said means for rotating said plate and means, carried by said support and normally insulated from said base and said rotatable plate, movable into contact with said plate for carrying any charge developed thereon to said measuring means.

4. In a device for testing the electrical conductivity and static accumulating properties of textile fibers wherein there is employed a means for measuring an electric potential, a plate, a cup for holding a sample of fibers to be tested mounted against rotation on said plate, a rotatable plate normally out of contact with said cup, means for moving said plate and said cup in the direction of said rotatable plate, said means including a bar attached to said first mentioned plate, a lever arm pivotally attached to said bar, and a counter-balance weight carried on said lever arm, means for rotating said plate whereby a frictional contact with a sample of fibers is effected, supports on which said plate rotating means is mounted, means for insulating said plate from said means for rotating said plate and means, carried by said support and normally insulated from said base and said rotatable plate, 5 600,901

movable into contact with said plate for carrying any charge developed thereon to said measuring means.

RALPH V. O'I'I.

REFERENCES CITED UNITED STATES PATENTS Number Name Date 1,790,540 Hacklander Jan. 27, 1931 1,502,330 Bernini July 22, 1924 1,568,366 De Michele Jan. 5, 1926 1,705,480 Scott-Huntington Mar. 19, 1929 2,166,385 Wintermute July 18, 1939 423,708 Tirmann -1--- Mar. 18, 1890 1,202,672 Chapman Oct. 24, 1916 1,922,933 Dirks Aug. 15, 1933 2,040,962 Strom May 19, 1936 340,842 West Apr. 27, 1886 FOREIGN PATENTS Number Country Date France Feb. 18. 1926 

